Summary The charter dive boat SEADEUCER proceeded from the Collins Bay Marina near Kingston, Ontario, on 20 July 1996, to a dive site off Simcoe Island in the St. Lawrence River, with nine divers and one operator on board. At the completion of the dive, the vessel took on increasing amounts of water through an opening in the transom used to enable divers to re-board at the stern. The combined movements of the free surface water and of the occupants in the same direction caused the vessel to capsize. All 10 persons on board were thrown into the water, but all survived. Ce rapport est galement disponible en franais. Other Factual Information Particulars of the Vessel On the morning of 20 July 1996 at about 1115(1), the SEADEUCER departed from the Collins Bay Marina near Kingston, with nine divers and one operator on board. The vessel also carried diving equipment which was securely stowed. The marine forecast given by the Ontario Climate Centre issued small craft warnings for eastern Lake Ontario from 0400 until the evening for 20 July. The operator of the boat indicated that the weather information he had listened to on a local radio station at 1000 did not give him any cause for concern as he was going to operate in local confined waters. At 1000, the wind speed for the Kingston area, as recorded by Environment Canada, was seven knots, and at 1100, four knots. The operator complained that local weather forecasts issued by Environment Canada were not as frequently available as in the past for specific time periods and local areas. The vessel arrived over the dive site off Simcoe Island in the St. Lawrence River, about one mile offshore, at approximately 1230 and was secured by a short securing rope to a mooring buoy connected to a sunken wreck. The nine divers, which included an instructor, entered the water. The operator (also a qualified diving instructor) remained on the boat to act as the dive tender. During the dive, the wind rapidly increased to more than 20 knots, gusting to 30 knots, from the north to north-west. After the dive, 30 minutes later, eight of the nine divers re-boarded the SEADEUCER which was now pitching and rolling in moderate waves, estimated at 1.5 m. The portable door in the transom at the stern, measuring approximately 0.5 m by 0.6 m, had been removed to enable the divers to come aboard. However, as the door had been removed, water could ingress each time the stern dipped into the trough between the crests of several larger swells. The operator was concerned about the port list which was developing and he instructed the divers on board to move forward. The water level in the boat had reached an estimated 0.2 to 0.4 m above the deck when the list developed. The vessel was still secured to the mooring buoy. The operator then asked that some divers move to starboard as he attempted to move the boat forward with the engine to try to shed the accumulated water. However, the vessel suddenly capsized to starboard when the majority of the divers moved to that side and the free surface water followed. The occupants of the boat were thrown into the water. One diver reported that, during the capsizing, he temporarily had lost consciousness when struck on the head by a hard object, probably an air tank. There was some concern for an exhausted diver who drifted away from the group, but two other divers quickly rescued him. All the divers wore wet suits, except the operator who wore a shirt and pants. The wet suits provided the divers with warmth and positive flotation. The water temperature was 22C. A short time later, several divers swam, without equipment, below the surface and inside the overturned vessel to get flares which were sealed in waterproof containers. All the persons in the water managed to climb on top of the overturned boat. The operator was eventually provided with a lifejacket retrieved from the cuddy cabin by one of the divers. After two hours, a power boat about 13 m long passed between the capsized boat and Simcoe Island. Three to five conventional red flares were fired in its path about 300 m away, but the boat did not slow down. Red night-time flares are less visible in daylight than orange smoke flares. The group discussed their options and it was decided that two of the stronger swimmers would swim to shore in a following sea to get some help. They both were wearing wet suits, and at first, one of them was wearing a Transport Canada-tested vest-type lifejacket, but he found that swimming with it on was too tiring and he later took the lifejacket off. Once ashore, the swimmers alerted the Canadian Coast Guard (CCG). After three hours, the rest of the group was picked up by a CCG vessel and brought ashore. The operator was treated for mild hypothermia and released from hospital a short time later. As the boat was over 6 m long, it was not required to have a capacity plate which would indicate the maximum number of persons that could be carried safely. The vessel construction was such that fully enclosed compartments between the deck and hull comprised built-in flotation. This vessel was never inspected, nor was such an inspection required by regulations. The lifejackets were all stowed forward in the cuddy cabin and were not immediately available when needed by those on board the vessel. At the time of the investigation, the vessel was found to be tender, easily heeling to 8 with one person standing on the side of the boat. The SEADEUCER had been used in the capacity of a charter dive boat for several years without incident. No documentation, stability criteria or construction plans were available for the boat as the builder has been out of business for a number of years.